A pest is "a plant or animal detrimental to humans or human concerns"; alternative meanings include organisms that cause nuisance and epidemic disease associated with high mortality. In its broadest sense, a pest is a competitor of humanity.
For example:
- Ants, cockroaches, flies and wasps are household pests, typically as they consume human food
- Aphids, larvae, grasshoppers and crickets cause damage to crop plants
- Lice, fleas and bed bugs can all cause skin irritation
- Mosquitoes, tsetse flies and kissing bugs cause irritation and carry disease
- Termites, woodworm and wood ants cause structural damage
- Bookworms, silverfish, carpet beetles and clothes moths cause non-structural damage
- Gypsy moths attack hardwood trees
- Mice, rats, and other small rodents cause infestations
- Rabbits decimate native plant , where they are an introduced species.
- Foxes eat waste
- Feral cats and feral dogs eat human food and carry disease
- Vampire bats suck blood of livestock.
- Wild boars damage crops, spread disease, and prey upon livestock.
- Pigeons and seagulls eat human food and carry disease.
- Many birds, such as crows, eat crops
- The Common Myna was declared by IUCN Species Survival Commission as one of the world's most invasive species and one of only three birds in the top 100 species that pose an impact to biodiversity, agriculture and human interests. In particular, the species poses a serious threat to the ecosystems of Australia where it was named "The Most Important Pest/Problem".